It’s all been leading up to this: Four years after “Iron Man” — with “The Incredible Hulk,” “Thor” and “Captain America” in between — “The Avengers” assembles Marvel’s team of superheroes into the summer’s first blockbuster.

Written and directed by “Buffy” creator Joss Whedon, the film finds our heroes in New York City, trading barbs while battling Loki, the superbaddie from “Thor.” We asked each member to reflect on their roles, working with such a large all-star cast and why Whedon is “the Line Police.”

Chris Evans (Captain America) on his role in the team:

“I give all these orders. It’s like, ‘Hulk, you do this impossible thing. Thor, you bottleneck a portal and Iron Man, you fly over here — and I’ll take the stairs.’” [Laughs]

Who would he trade places with if he could? “See, I want to say Iron Man, because I love those movies,” he says. “But who can do it better, you know what I mean? You think the shoes would be too big to fill.”

Mark Ruffalo (The Incredible Hulk) on taking the mantle:

As the third actor to play this role in a decade — after Eric Bana and Edward Norton —Ruffalo says: “It was terrifying. I knew what my responsibility was, or I felt it just by making the mistake of going online and reading some of the fanboy responses to the announcement that I was playing the next version of Bruce Banner. And that was a mistake. I will never do that again. But I never had a role more scrutinized and criticized before I even shot a single frame.”

Robert Downey Jr. (Iron Man) on not going it alone anymore:

“I remember I would get nervous about [the idea of pairing us up] and excited about it and doubtful of it,” says the erstwhile Tony Stark. “By the time Chris and Chris had launched their individual franchises with success and charisma, and by the time we had Mark, I was like, wow. So just being a worker among workers is kind of where I started out and it was nice to not have to really have to carry a movie. And everyone was really, really, really equal in this venture.”

Jeremy Renner (Hawkeye) on how surreal it was to assemble the team for the first time:

“I think it’s just getting all of the actors in one room all in costume, it was like Halloween,” Renner says. “I was friends with them as humans, and now they’re dressed up like silly people. When everybody was together, that was the most memorable. And creepy and funny. Getting to play with Thor’s hammer while he stroked my bow. Oh here we go, that’s going to be great. That’s going to get me in trouble.”

Chris Hemsworth on being a graceful Norse god:

“I have one [fight] scene where I was on the wire — because I hadn’t learned to fly yet — and I was supposed to come down and land on a cliff,” he says. “I was supposed to land, step and have a conversation. The first couple of takes — and this is going on the DVD extras somewhere — I just face-planted into the dirt. Very ungraceful and un-superhero-like.”

Samuel L. Jackson (Nick Fury) on being the straight man:

Director Joss Whedon admits that a lot of the funnier character moments in “The Avengers” came from improvisation among the cast — but Samuel L. Jackson, who plays team organizer Nick Fury in the film, would beg to differ. “I kept wanting to say [to Thor], ‘I don’t come to your world to blow s— up,’ but they won’t let me say it,” Jackson admits. “I don’t get to say this nice, cute s—. Every time I would change something, [Whedon] would come to me like the Line Police. He was always on me!”